Newbie question on how images work with video

[jcarst85]

Hi everyone,

I am a serious newcomer to editing and was hoping someone could help me with a very simple problem I am having. I just want to know a little more on how images work with video. For example, say I am producing an image slideshow for display on a 16:9, 85 inch 1920x1080p full HD TV. Do I just make the image 1920 x 1080 pixels in Photoshop and if so, what resolution do I use – 72PPI?

What I’m kind of getting at is, if you make an image 1920x1080 pixels in Photoshop, does that mean it will display at full quality on any device that plays video Full HD (1920x1080p), regardless of the size of the device, i.e. a 20” inch TV or 100” TV?

Or, for the aforementioned 85 inch TV, do I need to make the image 85 inches by 48 inches (a 16:9 aspect ratio) and again, what do I set the resolution at – 72PPI?

Conversely, a video project I am working on requires an image slideshow to be 800x450 pixels on a 7 inch wide screen. So again a standard 16:9. What do I make the image size for this? 800x450 pixels (what PPI?) or 7x4 inches?

Thanks a lot
Jamie

[racer-x]

Hi everyone,

I am a serious newcomer to editing and was hoping someone could help me with a very simple problem I am having. I just want to know a little more on how images work with video. For example, say I am producing an image slideshow for display on a 16:9, 85 inch 1920x1080p full HD TV. Do I just make the image 1920 x 1080 pixels in Photoshop and if so, what resolution do I use – 72PPI?

What I’m kind of getting at is, if you make an image 1920x1080 pixels in Photoshop, does that mean it will display at full quality on any device that plays video Full HD (1920x1080p), regardless of the size of the device, i.e. a 20” inch TV or 100” TV?

Or, for the aforementioned 85 inch TV, do I need to make the image 85 inches by 48 inches (a 16:9 aspect ratio) and again, what do I set the resolution at – 72PPI?

Conversely, a video project I am working on requires an image slideshow to be 800x450 pixels on a 7 inch wide screen. So again a standard 16:9. What do I make the image size for this? 800x450 pixels (what PPI?) or 7x4 inches?

Thanks a lot
Jamie

PPI doesn't matter in video, only pixel resolution does. If you are using PhotoShop, use the Crop tool and set it to 19.2 in x 10.8 in @ 100 ppi. Use that for all 16:9 projects, you can always downscale for smaller sized projects on export.

[jcarst85]

Thanks racer-x. Sorry for the simplicity of my question but I guess we all need to start somewhere!

So even though the image is 19.2 x 10.8 inches, that will still display full quality on full HD televisions well beyond that size, for example an 85 inch?

[El Heggunte]

PPI (or DPI) is relevant only for printing.

A 60-inch 1920x1080 TV and a 30-inch 1920x1080 monitor have the same quantity of pixels,
but of course, the pixels of the TV are "taller and wider" than the pixels of the monitor.

[racer-x]

Thanks racer-x. Sorry for the simplicity of my question but I guess we all need to start somewhere!

So even though the image is 19.2 x 10.8 inches, that will still display full quality on full HD televisions well beyond that size, for example an 85 inch?

19.2 x 100 ppi= 1920
10.8 x 100 ppi= 1080

If your tv supports a max resolution of 1920 x 1080, then that's the highest you can go. Now if your tv supports more like 4k and up, then you can use those resolutions.

[jcarst85]

Great thanks guys!

[jcarst85]

If you are using PhotoShop, use the Crop tool and set it to 19.2 in x 10.8 in @ 100 ppi. Use that for all 16:9 projects, you can always downscale for smaller sized projects on export.

Hi, I've just been playing around with this. Seems like I can just set the project to web at 1920 x 1080 pixels @ 72 ppi? Seeing as ppi doesn't matter, is this an equally viable option than setting photoshop to 19.2 x 10.8 in @ ppi? Or are there disadvantages to this approach?

[smrpix]

As racer-x said in the first reply, ppi is irrelevant in video. You want 1920x1080. How you get there doesn't matter.

[Cornucopia]

In racer-x's example sizing, unfortunately, ppi = 100 is REQUIRED. While I think that was arrived at to make the calculation more naturally in line with Pshop's default "inches", it bypasses the importance of PIXELS as the fundamental determiner of resolution in film/video (and not in a good way).

The video industry has been fine for years "assuming" 72dpi as the default ppi to choose, even if doesn't hold up for all video analogies. I'd go with that. And more importantly, I'd set the H & V dimensions to direct PIXEL notation (versus Inch/cm/point/pica) and then directly input the size needed. In fact, it's so much easier to just simply use the "1920 x 1080 HDTV 1080i" video preset that comes stock with ALL modern versions of Photoshop (it's available on as early as v7 for sure). You can ignore the "i", as that has no relevance in Pshop.

How you get there doesn't matter unless you are the type of person who does something via rote and then needs to adjust out of the comfort zone - then it matters. Understanding the big picture helps one reason things out independently at will.

Scott

[racer-x]

In racer-x's example sizing, unfortunately, ppi = 100 is REQUIRED. While I think that was arrived at to make the calculation more naturally in line with Pshop's default "inches", it bypasses the importance of PIXELS as the fundamental determiner of resolution in film/video (and not in a good way).

The video industry has been fine for years "assuming" 72dpi as the default ppi to choose, even if doesn't hold up for all video analogies. I'd go with that. And more importantly, I'd set the H & V dimensions to direct PIXEL notation (versus Inch/cm/point/pica) and then directly input the size needed. In fact, it's so much easier to just simply use the "1920 x 1080 HDTV 1080i" video preset that comes stock with ALL modern versions of Photoshop (it's available on as early as v7 for sure). You can ignore the "i", as that has no relevance in Pshop.

How you get there doesn't matter unless you are the type of person who does something via rote and then needs to adjust out of the comfort zone - then it matters. Understanding the big picture helps one reason things out independently at will.

Scott

I do a lot of SlideShows, so quality, speed and efficiency is very important. I posted my method because it is tried and true. I generally load an entire folder (100+) of images into Photoshop (version 7) at once. I then use the Crop Tool to quickly crop my composition into a 1920x1080 finished size and save to new folder.

The Crop Tool deals with inches, so using 100 ppi/dpi makes it easier to guess size. Using 100 dpi or 72 dpi makes no difference quality wise....

[newpball]

If you are using PhotoShop, use the Crop tool and set it to 19.2 in x 10.8 in @ 100 ppi. Use that for all 16:9 projects, you can always downscale for smaller sized projects on export.

Hi, I've just been playing around with this. Seems like I can just set the project to web at 1920 x 1080 pixels @ 72 ppi? Seeing as ppi doesn't matter, is this an equally viable option than setting photoshop to 19.2 x 10.8 in @ ppi? Or are there disadvantages to this approach?

For video just use pixels, ignore the rest, problem solved!

Points and picas are for resp. printing and publishing.

The Crop Tool deals with inches, so using 100 ppi/dpi makes it easier to guess size. Using 100 dpi or 72 dpi makes no difference quality wise....

It doesn't, it deals with what the user defines.

[jcarst85]

Thanks everyone. This has been very helpful.